Patent application title: METHOD AND SYSTEM FOR OPTIMAL COORDINATION CONTROL AND SOFT REPAIR OF MULTIPLE ROOFTOP HEATING AND COOLING UNITS

Abstract:

Techniques are described that may be implemented in an adaptive control
device to regulate multiple zone environmental units based upon multiple
temperature values and multiple airflow values, where each temperature
value and each airflow value is related to the temperature and the
airflow in a specific zone. In an implementation, the input interface of
the adaptive control device is configured to receive multiple temperature
values and multiple air flow values from multiple zone sensors. The
adaptive control device may calculate multiple operational values based
on the multiple temperature values and the multiple air flow values. An
operational value indicates a power state (e.g. power on/power off) for a
zone environmental unit's fan, compressor, heater, exhaust fan, and
damper. The adaptive control device's output interface is operable to
transmit multiple sequencing commands to the plurality of zone
environmental units.

Claims:

1. A method comprising:receiving a plurality of temperature values and a
plurality of airflow values, the plurality of temperature values and the
plurality of airflow values associated with a plurality of
zones;calculating a plurality of operational values based on the
plurality of temperature values and the plurality of airflow values, the
plurality of operational values configured to indicate a plurality of
power states for a plurality of fans, compressors, heaters, exhaust fans,
and dampers, the plurality of fans, compressors, heaters, exhaust fans,
and dampers associated with a plurality of zone environmental units;
andtransmitting a plurality of sequence commands to the plurality of zone
environmental units for sequencing the plurality of fans, compressors,
heaters, exhaust fans, and dampers, the plurality of sequence commands
based on the plurality of operational values.The method of claim 1,
wherein receiving a plurality of temperature values and a plurality of
airflow values, the plurality of temperature values and the plurality of
airflow values associated with a plurality of zones comprises:receiving a
first temperature value and a first airflow value from a first zone
sensor, the first zone sensor associated with a first zone;receiving a
second temperature value and a second airflow value from a second zone
sensor, the second zone sensor associated with a second zone.The method
of claim 2, wherein calculating a plurality of operational values based
on the plurality of temperature values and the plurality of airflow
values comprises:calculating a first operational value and a second
operational value, the first operational value based on the first
temperature value and the second airflow value, the second operational
value based on the second temperature value and the second airflow value,
the first operational value configured to indicate a first power state of
a first fan, a first compressor, a first heater, a first exhaust fan, and
a first damper associated with a first zone environmental unit, the
second operational value configured to indicate a second power state of a
second fan, a second compressor, a second heater, a second exhaust fan,
and a second damper associated with a second environmental unit.The
method of claim 3, wherein transmitting a plurality of sequence commands
to the plurality of zone environmental units comprises:transmitting a
first sequence command to the first zone environmental unit for
sequencing the first fan, the first compressor, the first heater, the
first exhaust fan, and the first damper, the first sequence command based
on the first operational value;transmitting a second sequence command to
the second zone environmental unit for sequencing the second fan, the
second compressor, the second heater, the second exhaust fan, and the
second damper, the second sequence command based on the second
operational value.The method of claim 1, wherein the plurality of zone
environmental units comprise a plurality of rooftop units.The method of
claim 1, wherein the plurality of zones comprise a plurality of regions
in an enclosed structure.The method of claim 1, wherein the plurality
power states comprise a plurality of power on states.The method of claim
1, wherein the plurality power states comprise a plurality of power down
states.An adaptive control device comprising:an input interface operable
to receive a plurality of temperature values and a plurality of airflow
values, the plurality of temperature values and the plurality of air flow
values associated with a plurality of zones;a memory operable to store
one or more modules;a processor operable to execute the one or more
modules to:calculate a plurality of operational values based on the
plurality of temperature values and the plurality of air flow values, the
plurality of operational values configured to indicate a plurality of
power states for a plurality of fans, compressors, heaters, exhaust fans,
and dampers, the plurality of fans, compressors, heaters, exhaust fans,
and dampers associated with a plurality of zone environmental units;
andan output interface operable to transit a plurality of sequencing
commands to the plurality of zone environmental units for sequencing the
plurality of fans, compressors, heaters, exhaust fans, and dampers, the
plurality of sequencing commands based on the plurality of operational
values.The adaptive control device of claim 9, wherein the input
interface comprises:the input interface operable to receive a first
temperature value and a first airflow value from a first zone sensor, the
first zone sensor associated with a first zone;the input interface
operable to receive a second temperature value and a second airflow value
from a second zone sensor, the second zone sensor associated with a
second zone.The adaptive control device of claim 10, wherein the
processor operable to execute the one or more modules to comprises:the
processor operable to execute the one or more modules to:calculate a
first operational value and a second operational value, the first
operational value based on the first temperature value and the second
airflow value, the second operational value based on the second
temperature value and the second airflow value, the first operational
value configured to indicate a first power state of a first fan, a first
compressor, a first heater, a first exhaust fan, and a first damper
associated with a first zone environmental unit, the second operational
value configured to indicate a second power state of a second fan, a
second compressor, a second heater, a second exhaust fan, and a second
damper associated with a second environmental unit.The adaptive control
device of claim 11, wherein the output interface comprises:the output
interface operable to transmit a first sequence command to the first zone
environmental unit for sequencing the first fan, the first compressor,
the first heater, the first exhaust fan, and the first damper, the first
sequence command based on the first operational value;the output
interface operable to a second sequence command to the second zone
environmental unit for sequencing the second fan, the second compressor,
the second heater, the second exhaust fan, and the second damper, the
second sequence command based on the second operational value.The
adaptive control device of claim 9, wherein the plurality of zone
environmental units comprise a plurality of rooftop units.The adaptive
control device of claim 9, wherein the plurality of zones comprise a
plurality of regions in an enclosed structure.The adaptive control device
of claim 9, wherein the plurality power states comprise a plurality of
power on states.The adaptive control device of claim 9, wherein the
plurality power states comprise a plurality of power off states.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001]The present application claims the benefit under 35 U.S.C.
§119(e) of U.S. Provisional Application Ser. No. 61/228,674, filed
Jul. 27, 2009, which is herein incorporated by reference in its entirety.

BACKGROUND

[0002]Multi-Roof Top Units (RTUs) are generally used for light commercial
buildings with an open space. RTUs are configured as constant air volume
systems, which causes these RTUs to be inefficient in ventilation,
capacity, and humidity control.

SUMMARY

[0003]Techniques are described that may be implemented in an adaptive
control device to regulate multiple zone environmental units (RTUs) based
upon multiple temperature values and multiple airflow values, where each
temperature value and each airflow value is related to the temperature
and the airflow in a specific zone. In an implementation, the input
interface of the adaptive control device is configured to receive
multiple temperature values and multiple air flow values from multiple
zone sensors. The adaptive control device may calculate multiple
operational values based on the multiple temperature values and the
multiple air flow values. An operational value indicates a power state
(e.g. power on/power off) for a zone environmental unit's fan,
compressor, heater, exhaust fan, and damper. The adaptive control
device's output interface is operable to transmit multiple sequencing
commands to the plurality of zone environmental units.

[0004]This Summary is provided solely to introduce subject matter that is
fully described in the Detailed Description and Drawings. Accordingly,
the Summary should not be considered to describe essential features nor
be used to determine scope of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005]The detailed description is described with reference to the
accompanying figures. In the figures, the left-most digit(s) of a
reference number identifies the figure in which the reference number
first appears. The use of the same reference numbers in different
instances in the description and the figures may indicate similar or
identical items.

[0006]FIG. 1 is a schematic view of an adaptive controller.

[0007]FIG. 2 is a schematic view of an environment having a plurality of
environmental zones and corresponding environmental zone units.

[0008]FIG. 3 is a flow diagram illustrating a procedure in an examplary
implementation of the adaptive control device of FIG. 1.

DETAILED DESCRIPTION

[0009]Zone environmental units, or Heating, Venting, and Air Conditioning
systems (i.e. roof top units), are generally constant air systems, which
causes these zone environmental units to be inefficient regulating
humidity and ventilation.

[0010]Accordingly, techniques are described that may be implemented in an
adaptive control device that provides sequencing commands to multiple
zone environmental units. In an implementation, the adaptive control
device's input interface may receive multiple temperature values and
multiple airflow values from a plurality of zone sensors. The zone
sensors may be dedicated to a specific zone within an enclosed structure.
The adaptive control device may then calculate multiple operational
values based on the received temperature values and airflow values. An
operational value may indicate or signify a power state of a zone
environmental unit's fan, compressor, heater, exhaust fan, and/or one or
more coupled dampers. The adaptive control device's output interface may
transmit multiple sequencing commands to the appropriate zone
environmental units for sequencing the fans, compressors, heaters,
exhaust fans, and dampers. The sequencing commands may be based on the
calculated operation values.

[0011]For example, an adaptive control device may receive temperature
values and airflow values from two zone sensors; one zone sensor
dedicated to a first zone in an enclosed structure and the other zone
sensor dedicated to a second zone (distinct from the first zone) in the
enclosed structure. The adaptive control device may then calculate
operational values, based on the temperature values and airflow values
from each respective zone, to determine whether the zone environmental
units associated with these two zones should be powered on or powered
off. The adaptive control device may then transmit a first sequencing
command to the zone environmental unit dedicated to the first zone based
on the first operational value. This first operational value may be
determined from temperature values and airflow values associated with the
first zone. The adaptive control device may also transmit a second
sequencing command to the zone environmental unit dedicated to the second
zone based on the second operational value, where the second operational
value may be determined from temperature values and airflow values
associated with the second zone. Each operational value may indicate to
power on/off the respective zone environmental unit's fan, compressor,
heater, exhaust fan, and damper depending the temperature value and
airflow value associated with each respective zone.

[0012]In the following discussion, an example adaptive control device
environment is first described. Exemplary procedures are then described
that may be employed with the example environment, as well as with other
environments and devices without departing from the spirit and scope
thereof.

EXAMPLE ENVIRONMENT

[0013]FIG. 1 illustrates an example adaptive control device environment
100 that is operable to perform the techniques discussed herein. The
environment 100 includes an adaptive control device 102 operable to
sequence commands to multiple zone environmental units 104. The adaptive
control device 102 may be configured in a variety of ways. For instance,
an adaptive control device 102 may be configured as a central processing
unit, a microcontroller with pre-programmed instructions, a stand-alone
computing device, combinations thereof, and so forth. In the following
description, a referenced component, such as a adaptive control device
102, may refer to one or more entities, and therefore by convention
reference may be made to a single entity (e.g., the adaptive control
device 102) or multiple entities (e.g., the mobile electronic devices
102, the plurality of mobile electronic devices 102, and so on) using the
same reference number.

[0014]In FIG. 1, the adaptive control device 102 is illustrated as
including a processor 106 and a memory 108. The processor 106 provides
processing functionality for the adaptive control device 102 and may
include any number of processors, micro-controllers, or other processing
systems and resident or external memory for storing data and other
information accessed or generated by the adaptive control device 102. The
processor 106 may execute one or more software programs which implement
the techniques and modules described herein. The processor 106 is not
limited by the materials from which it is formed or the processing
mechanisms employed therein and, as such, may be implemented via
semiconductor(s) and/or transistors (e.g., electronic integrated circuits
(ICs)), and so forth.

[0015]The memory 108 is an example of device-readable storage media that
provides storage functionality to store various data associated with the
operation of the adaptive control device 102, such as the software
program and code segments mentioned above, or other data to instruct the
processor 106 and other elements of the adaptive control device 102 to
perform the techniques described herein. Although a single memory 108 is
shown, a wide variety of types and combinations of memory may be
employed. The memory 108 may be integral with the processor 106,
stand-alone memory, or a combination of both. The memory may include, for
example, removable and non-removable memory elements such as RAM, ROM,
Flash (e.g., SD Card, mini-SD card, micro-SD Card), magnetic, optical,
USB memory devices, and so forth.

[0016]FIG. 1 also illustrates the adaptive control device 102 as including
an input interface 110 and an output interface 112. The input interface
110 may provide functionality to receive data via a network 118, and the
output interface 112 may provide functionality to transmit data via the
network 118. Embodiments of the input interface 110 and the output
interface 112 may include, for example, a port, a cable, a wireless
receiver, and so forth. The network 118 may include a wireless network, a
wired network, the Internet, an intranet, and so forth.

[0017]The environment 100 also includes a plurality of zone sensors 114 as
illustrated in FIG. 1. Each zone sensor 114 may be dedicated to a
specific zone 202 (depicted in FIG. 2) to collect and/or to measure
environmental characteristics of the specific zone 202. For example, a
zone sensor 114 may measure the temperature and the airflow in a specific
zone. The input interface 112 may then receive a temperature value and an
airflow value from the zone sensor 114 via the network 118. Embodiments
of the plurality of zone sensors 114 may include any generally known
temperature/airflow sensor known in the art or the like.

[0018]The adaptive control device 102 is further illustrated as including
functionality to provide sequencing commands to control the power state
of a zone environmental unit 104 via a calculation module 116. For
example, adaptive control device 102 may receive temperature values and
airflow values via the input interface 110. The calculation module 116
may calculate a plurality of operational values utilizing a set of
equations, as described below, to determine whether a plurality of zone
environmental units 104 should be powered on if the zone environmental
units 104 are currently in a powered down state or whether the zone
environmental units 104 should be powered off if the zone environmental
units 104 are currently in a powered on state. Once the operational
values are calculated, the output interface 112 may transmit a sequencing
command to the plurality of zone environmental units 104 via the network
118. The sequencing command may be a command to power on or power off,
where the sequencing command(s) depend(s) on the calculated operational
value(s).

[0019]An environment 200 is illustrated in FIG. 2. The environment 200
includes a plurality of zones 202 with dedicated, or associated, zone
environmental units 104 (each zone and zone environmental unit is
depicted as an RTU with respective column and row). As depicted, there
are l (row)×m (column) environmental zone units. Each zone 202 may
represent a specific region or specific boundary within an enclosed
structure 204. The enclosed structure 204, for example, may include a
commercial building and the like. The enclosed structure 204 may include
multiple zone environmental units 104. The zone environmental units 104
may include HVAC units, such as roof top units, and the like. The zone
environmental units 104 may include fans, compressors, heaters, exhaust
fans, dampers, (not shown) and so forth.

[0020]The zone environmental units 104 may be associated with one specific
zone 202 within the enclosed structure 204, or the zone environmental
units 104 may be associated with multiple specific zones 202 within the
enclosed structure 204. For example, the zone environmental unit 104 may
be dedicated to cooling a first zone 202 only. Conversely, the zone
environmental unit 104 may be dedicated to cooling the first zone 202 and
a second zone 202.

[0021]The calculation module 116 may calculate or determine the
operational values based upon the following equations. The ideal number
of operating fans (ni), where one zone environmental unit may
include a fan, may be determined by the minimum total air flow rate
required for the whole conditioning space 1 and the average RTU
airflow rate, RTU.

and 1 is the maximum value for satisfying ventilation, heating, and
cooling requirements for the enclosed structure 204. The current baseline
is that during the enclosed structure's hours, all supply fans are
operating:

t=MAX(v, h, c) (3),

where v is the minimum airflow rate required by ventilation, h
is the minimum flow by heating, and c is the minimum airflow rate by
cooling. These parameters, or values, can be calculated by Equations (4),
(5) and (6):

v=RpPz+RaAz (4)

h=Rkh (5)

c=Rcc (6);

where Rp is the outdoor airflow rate required per person (e.g., 7.5
cfm/person for supermarket); Pz is the zone population (e.g., 8
person/1000 ft2 for supermarket); Ra is the outdoor airflow
rate required per unit area (e.g., 0.06 cfm/ft2 for supermarket).
For a supermarket application, v is about 15 cfm/person or 0.12
cfm/ft2; Rh is the supply airflow rate required per unit ton of
heating load (about 200 cfm/ton for supermarket); Rc is the supply
airflow rate required per unit ton of cooling load (about 340 cfm/ton for
supermarket); h is the instantaneous heating load; and c is the
instantaneous cooling load. h and c can be calculated by:

h=kenv(Tb-Tamb) (7)

c=kenv[Tamb-Th-(T.sub.sp,c-T.sub.sp,h)] (8)

where kenv is the enclosed structure's 204 envelop load coefficient;
Tamb is the ambient temperature; Tb is the balance temperature;
T.sub.sp,h is the zone heating set point; and T.sub.sp,k is the zone
cooling set point.

[0022]Each zone environmental unit may include multiple mode settings. For
example, the zone environmental unit may have a cool mode for cooling
periods, a heating mode for heating periods, economy, or economizer, mode
for energy saving periods, and so forth. The locations of operating fans
within the enclosed structure 204 may be determined by: Calculating the
temperature offsets for each zone from its set points:

Start the fans whose ΔTij belongs to the top n1 and if
[0023]1. Δtoff,ij>Δtoff,min (e.g., 5 mins) and
[0024]2. ΔTij>ΔTmin (e.g., -2 F)Start the fans
whose ΔTij does not belong to the top ni but if [0025]1.
ΔTij>ΔTmax (3 F)
orΔtoff,ij>Δtoff,max (e.g., 2 hrs) and
ΔTij>ΔTmin (e.g., -2 F).

Start all the compressor(s) of the zone environmental unit(s) 104 if
mode=cooling and [0029]1. FanStatus=`on` and [0030]2.
Δtoff,ij>Δtoff,min (e.g., 5 mins) [0031]3. One
ΔTij>ΔTmin (e.g., -2 F).The adaptive device
control 102 may determine that each individual compressor should stage
off one-by-one if ΔTij drops at a rate higher than kT
(e.g, 2 F in 10 minutes) and maintain the supply air dry-bulb temperature
low than T.sub.sp,s (e.g., 55 F) if the dewpoint of the outdoor air is
higher than T.sub.sp,s (e.g., 55 F).

[0032]The heater operation, where each zone environmental unit 104 may
include a heater, may be determined by:

Start all the heater(s) of the RTU if mode=heating and [0033]1.
FanStatus=`on` and [0034]2. Δtoff,ij>Δtoff,min
(e.g., 5 mins) [0035]3. ΔTij>ΔTmin (e.g., -2
F).The adaptive control device 102 may determine that individual heaters
may be staged off one-by-one if ΔTij drops at a rate higher
than kT (e.g, 2 F in 10 minutes).

[0036]The exhaust fan operation, where each zone operational unit 204 may
include an exhaust fan, may be determined by:

The number of exhaust fans to be operated should be equal to the actual
number of operating supply fans (na). Define a parameter,
w.sub.ef,ij, to quantify the priority of the exhaust fan associated with
RTUij. Update equation (11) every time the following conditions are
checked: [0037]1. If the supply fan of RTUij is off, then
Δw.sub.ef,ij=1, otherwise, Δw.sub.ef,ij=0 [0038]2. If
ΔRij≧ F, then
Δw.sub.ef,ij=ΔTij/[ΔTmax((α[F])+β[-
F])], otherwise
Δw.sub.ef,ij=ΔTij/[ΔTmin((α[F])+δ-
[F])]

[0038]w.sub.ef,ij=w.sub.ef,ij+Δw.sub.ef,ij (11)

In a typical design, the variable =0, the variable α=3, the variable
β=2, and the variable δ=1. The adaptive control device 102 may
determine that exhaust fans whose w.sub.ef,ij belongs to the top na
may need to powered on or started.

[0039]The damper operation, where each zone environmental unit 204 may be
associated with a damper, may be determined by:

The outdoor damper position should be maintained at its possible minimum
position (can be up to 100%):

β min = V v & V i & . ##EQU00004##

The current baseline is during the enclosed structure's 204 hours, the
outdoor damper is maintained at a minimum position βmin,b
(10-30% according to test and balance) when the economizer is not
enabled. Ideally, if the test and balance practice are accurate,
βmin≧βmin,b, the same amount of outdoor air is
delivered to the zone 202, so no additional ventilation load is
introduced from the whole enclosed structure perspective.

[0040]If mode=cooling, modulate the damper position to meet ov
in terms of the whole enclosed structure.

[0041]If mode=economizing, modulate the damper position=100%.

[0042]If mode=heating, modulate the damper position to meet ov
in terms of the whole enclosed structure 204.

[0043]Generally, any of the functions or equations described herein can be
implemented using software, firmware, hardware (e.g., fixed logic
circuitry), manual processing, or a combination of these implementations.
The terms "module" and "functionality" as used herein generally represent
software, firmware, hardware, or a combination thereof. The communication
between modules in the adaptive control device 102 of FIG. 1 can be
wired, wireless, or some combination thereof. In the case of a software
implementation, for instance, the module represents executable
instructions that perform specified tasks when executed on a processor,
such as the processor 106 with the adaptive control device 102 of FIG. 1.
The program code can be stored in one or more device-readable storage
media, an example of which is the memory 108 associated with the adaptive
control device 102 of FIG. 1.

EXAMPLE PROCEDURES

[0044]The following discussion describes procedures that may be
implemented in an adaptive control device providing control
functionality. Aspects of the procedures may be implemented in hardware,
firmware, or software, or a combination thereof. The procedures are shown
as a set of blocks that specify operations performed by one or more
devices and are not necessarily limited to the orders shown for
performing the operations by the respective blocks. In portions of the
following discussion, reference may be made to the environment 100 of
FIG. 1. The features of techniques described below are
platform-independent, meaning that the techniques may be implemented on a
variety of control device platforms having a variety of processors.

[0045]FIG. 3 depicts a procedure 300 in an example implementation in which
an adaptive control device 102 provides sequencing commands to multiple
zone environmental units. As shown in FIG. 3, the adaptive control device
receives a plurality of temperature values and a plurality of airflow
values from a zone sensor 114 (Block 302). The temperature values and the
airflow values may represent a temperature reading and an airflow reading
from a specific zone(s) 202.

[0046]Upon receiving the temperature values and airflow values, the
calculation module 116 may calculate an operational value or operational
state of a zone environmental unit's fan compressor, heater, exhaust fan,
and damper (Block 304). The adaptive control device 102 may then
determine whether more zone sensors 114 need to transmit temperature
values and airflow values (Decision Block 306) to the adaptive control
device 102. If more temperature values and airflow values need to be
transmitted ("YES" from Decision Block 306), the adaptive control device
may receive these temperature values and airflow values upon/or after
transmission (Block 302). Otherwise ("NO" from Decision Block 308), the
adaptive control device 102 may transmit sequence commands to the zone
environmental units 104 for sequencing the operation of each zone
environmental unit's 104 fan, compressor, heater, exhaust fan, and
damper.

[0047]Although techniques to transmit multiple sequencing commands to
multiple zone environmental units have been described in language
specific to structural features and/or methodological acts, it is to be
understood that the appended claims are not necessarily limited to the
specific features or acts described. Rather, the specific features and
acts are disclosed as exemplary forms of implementing the claimed devices
and techniques.